Efficient Method for the Synthesis of Michael Adducts Using Kaolin Preloaded with KOH
作者:G. Srihari、M. Marthanda Murthy
DOI:10.1080/00397910802439191
日期:2009.2.9
Abstract Michael addition of various active methylene compounds to β-nitrostyrenes is efficiently catalyzed by using Kaolin preloaded with KOH in acetonitrile at room temperature with moderate to good yields.
Addition of a variety of 1,3-dicarbonyl derivatives to conjugated nitroalkenes was efficiently performed under heterogeneous catalysis by acidic alumina in the presence of a minimum amount of solvent (Et2O, 0.5 mL/mmol). The procedure allows satisfactory to good yields of a diastereomeric mixture (Ë1:1) of polyfunctionalized adducts. Moreover, work-up can be avoided since the reaction mixture can be directly charged into a chromatographic column for immediate purification.
Genomic salmon testes DNA as a catalyst for Michael reactions in water
作者:Margherita De Rosa、Sara Di Marino、Anna Maria D’Ursi、Maria Strianese、Annunziata Soriente
DOI:10.1016/j.tet.2012.02.007
日期:2012.4
The DNA molecule, recognized as the carrier of genetic information in vivo, can function as an efficient organocatalyst for Michael additions of 1,3-dicarbonyl compounds to activated alkenes in aqueous media. The procedure described here is environmentally benign and offers several advantages in terms of simplicity, generality and efficiency. We have used fluorescence spectroscopy to evaluate the catalytic activity of a molecule of DNA. (C) 2012 Elsevier Ltd. All rights reserved.
Chiral Phosphoric Acid Catalyzed Diastereo- and Enantioselective 1,4- Conjugate Addition of β-Ketoesters to Nitroolefins
Chiral phosphoric acid as organocatalyst for the diastereo- and enantioselectivity 1,4-conjugate addition of a variety of β-ketoesters to nitroolefins was firstly developed, providing the corresponding adducts in high yield (up to 97%) with moderate diastereoselectivities (up to 2.6:1 dr) and enantioselectivities (up to 58% ee).